An Italian ship was attacked Monday off the Somali coast, the ship's owner said.
The last message from the captain indicated that the vessel, the Montecristo, was attacked by a ship with five armed people, the D'Alesio Group said in a statement.
The captain immediately activated security procedures, the statement said.
It was not immediately clear whether the attackers managed to hijack the ship, which was about 620 miles (998 km) east of the Somali coast.
Italian and international authorities are responding, the statement said.
The crew includes 23 people from Italy, Ukraine, and India, the D'Alesio Group said.